moulds drop at what size?

[tcbnick]

I've been reading alot about 9mm here. And that brings me to my ?. If you buy a lee 356-120 what size does it really throw. My custom moulds drop at what they said they would, and I know that fit is king. So with any production mould is there a Rule of Thumb that they drop 1 or 2 thous over stated size. I do understant that alloy will make a difference, and you can size down. But how do you buy a mould that will fit ? I know that a 9mm was probably not the best thing to use .356 .358, but maybe a .44, sold as a .429 but I use .432

Thanks Nick

[shooting on a shoestring]

Good question. Doesn't have a good answer though. The basic problem is tolerance. In machining there is a maximum and a minimum size for any given part. Thats the tolerance. Ususally stated in the design/drawing as nominal size x plus or minus so much. The machine, or machinist gets to use the whole range from barely big enough up through exactly sized right up to almost too big. Those are all good parts and are sold.

So if you get a mould cut on the minimum side it'll cast smaller than one cut on the maximum, although both are sold as being the correct size. A smaller shop can spend more time and care machining and can often beat the allowed tolerances and produce virtually indistinguishable parts that appear to be all one size. That'll cost more, but only once.

Mass produced means cheaper costs, bigger tolerances, more size vairation.

So what size is a Lee 356-120? Probably between too loose and too tight, but workable.

[MtGun44]

I varies due to mold tolerances and then again due to casting methods and alloys and temps.
No real answer beyond, "Usually .002 or more larger than the nominal diam in the name."

Bill

[Bret4207]

It's a krap shoot. Sorry. Might be big, might be small, you never know till you cast with it.

[JonB_in_Glencoe]

I've been reading alot about 9mm here. And that brings me to my ?. If you buy a lee 356-120 what size does it really throw.

From my experience,

Lee cuts them real close if you buy a new Lee 356 mold...it's probably gonna be .356 BUT there is the wild card that you'll get one "out of tolerance", in that case Lee's customer service has been real good about fixing the problem/replacing the mold. My most recent Lee purchase is a 501-440 RF...and Boolits from that drop "out of round" and measure .5005 to .5015 it also has some chatter marks that look like fluting.
See the sixth post
http://castboolits.gunloads.com/showthread.php?p=1747372#post1747372

[MT Gianni]

If you and I bougt sequential molds from their tooling there is no reason to expect that they would throw near the same diameter,

[sig2009]

My Lee 356 mold cast at 356 no matter what alloy I used.

[MtGun44]

My several LEE 356 molds all cast .358 or more. Like Bret says, it is a luck thing to a large
degree.

Bill

[dromia]

Lee's tolerances states + 0.003".

I've also found them to be - 0.003" as well, their moulds are a real lottery.

It also amazes me how if you want a large mould you get an under size one and vice versa. Its as if they seem to know so they can exercise their contrariness. :roll:

Obviously alloy and casting temperature has a bearing on the size of boolits dropped as well as the mould.

[onesonek]

Some may be lucky, but from with all the above with he exception of one post, I would say "krap shoot" best convinces me to stay with custom. Being a bit particular on such things myself, I will just stay with Tom's work at AM molds.

[onesonek]

My Lee 356 mold cast at 356 no matter what alloy I used.

What are you measuring with? I have yet to find two different alloy's drop the same dia., albeit sometimes small in difference

[Harter66]

My 356-124 drops 3587-360 depending on alloy. WW for 9mm/357 , 50-50 WW/pure for 38s. I've had the good fortune of getting full bodied Lee moulds.

[MikeS]

Some may be lucky, but from with all the above with he exception of one post, I would say "krap shoot" best convinces me to stay with custom. Being a bit particular on such things myself, I will just stay with Tom's work at AM molds.

I agree with you about sticking with Tom's moulds, they really are works of art. Having said that, I've never had a problem with Lee moulds being undersized. I have found that it seems like their TL moulds seem to cast closer to the stated size than their conventional lube groove moulds. When I size my boolits the TL ones seem to hardly need any sizing, and I could probably just go ahead and shoot them unsized, but with my luck, the first time I try that I'll get a tiny splash of lead between the mould faces, and end up with way oversized boolits that won't fit into my gun! So I'll keep sizing them even if they only size a very small amount.

I actually think that Lyman moulds are more of a crapshoot these days than Lee moulds are. I even have a SAECO mould that's almost too small, when I size them the driving bands just barely clean up (get that nice shiny just sized look).

[dromia]

I have sold quiet a few Lyman moulds, well a couple of dozen over the past year and out of interest I've asked the customers to let me know how they've cast and all except one has been spot on or slightly over. The alloys were range scrap to WW hardness mostly say 9-12 BHN except for the large BP moulds that were cast with almost pure lead.

Now mould sales aren't high here in the UK so it could be old stock on the wholesalers shelves, however I did have to wait for a couple of them to come in and it was one of them that had to be replaced. It was a 266469 that was way out of round, the replacement was spot on.

So as you say a lottery it seems, but at present I am confident retailing Lyman. Hope that this isn't tempting fate.

In our post modern society its the bean counters that set the policy and service doesn't seem to make money any more and profits are increased with the Ikea model of QC, let the customer do it.

We are fortunate to be serviced by some fine bespoke mould makers but the demand does seem greater than the supply.

Accurate do indeed make fine moulds and I buy from him, waiting for a 310 Cadet mould as I write. Just a shame he can't do smaller than 30 cal can only do flat nose but if your needs are within those limitations then Accurate will meet them well.